Induction heating head and arbor therefor



Oct. 4, 1949. H. A. STRICKLAND, JR 2,483,444

INDUCTION HEATING HEAD AND ARBOR THEREFOR Filed July 17, 1945 2 Sheets-Sheet l r 2 T W TS I v I A7 zg s I ggs l Q 1 3/ I I q '14 A7413 6- EB" 11 5 l 48 f I 37 HI w WI 16 INN, 36 5 5 i 33 27 Eli: 44

ET i 0 20* 5% 18 f E 26 26 '22 f I 33 4 lllllll I I 4 17417 Old .fllflirz'clilancZJn INVENTOR ATTORNEY Oct. 4, 1949;

H. A. STRICKLAND, JR

INDUCTION HEATING HEAD AND ARBOR THEREFOR Filed July 17, 1945 2 Sheets-Shea? flaroZd flSirzci'ilandJn INVENTOR BY I ATTORNEY Patented Oct. 4, 1949 INDUCTION HEATING HEAD AND ARBOR THEREFOR Harold A. Strickland, J r., Detroit, Mich, assignor, by mesne assignments, to The ()hio Crankshaft Company, Cleveland, Ohio, a corporation of Ohio Application July 17, 1945,.Serial No. 605,507

6 Claims. (Cl. 21913 This invention relates to an electro-magnetic induction heating head and supporting arbor for conducting current thereto, particularly to the manner of supporting the head from. the arbor.

Heretofore, it has been the practice in induction heating equipment utilizing an arbor having concentric current conductors and a head memher having an inductor coil to provide various means for threadably or otherwise supporting the head from the arbor which means added considerabl to the cost of the equipment and required considerable time for assembly and disassembly of the parts when it was desired to replace the heating head.

The primary object of the present invention is to provide a simple and economical expedient for removably supporting the induction heating head from a current-conducting arbor.

A further object is to provide a simple arrangement whereby the connections between the terminals of the inductor coil and the current conductors of the arbor constitute the sole means for supporting the head from the arbor.

With the above and other objects in View, which will be apparent to those skilled in the art to which the invention appertains, the present invention consists in certain features of construction and combinations of parts to be hereinafter described with reference to the accompanying drawings, and then claimed.

In. the drawings which illustrate asuitable embodiment of the invention for the purpose of description;

Figure 1 is an elevation of the induction heating head;

Figure 2 is a vertical section of the heating head taken substantially on the line 2-2 of Figure l. and showing the same assembled to the current-conducting arbor;

Figure 3 is a transverse section taken substan- 40 tially on line 33 of Figure 2;

Figure 4 is a transverse section taken substantially on line 4-4 of Figure 2;

Figure 5 is a transverse section taken substantially on line E5 of Figure 3; and

Figure 6 is an elevation, partially in section, of the heating head, showing the initial step in the process of removing the inductor coil from the head.

Referring to the accompanying drawings in which like numeralsrefer to like parts throughout the several views, the current conducting arbor lis comprised of an inner current conductor 2 formed of concentric tubular members the ends of the passage 5 being sealed by a closure sleeve 5, and an outer current conductor 1 similarly formedlof concentric tubular members 8 and 9 having a fluid passage l0 therebetween, the end of which is sealed by a closure sleeve II.

The conductors 2 and l are separated from each other by an insulating sleeve l2 and are each drilled through their ends to provide bores l3 and M, respectivel opening into the passages 5 and it, which bores receive the shanks of passaged fitting l5 and I6, respectively, the shanks thereof being brazed or otherwise secured in water tight connection with the bores. Theends of the passage'd fittings are externally threaded as shown. I

The induction heating head 11 includes a tubular mandrel l8 to one endof which an annular coil supporting element [9 is suitably secured, such as by shrink fitting or brazing. The upper end of the element 19 is provided with an annular undercut shoulder 20 and surrounding the element [9 in interlocking relation with the shoulder 20 is an annular magnetic circuit mem- 1 1 her 2i of low magnetic reluctance which is comprised of a series of tapered laminations. Secured to the element [9 by screws 22 is an annular end plate 23 having a shoulder 24 which interlocks with the laminated member 21 and together with shoulder 20 looks the laminations in position about the element I9.

The laminated" member 2! is provided with a circumferential window 25 and disposed in this window is a helicaLhollow inductor coil 26.

The annular element I9 is formed with a longitudinally extending boss portion 2'? at its upper end and with a through-running passageway 28 which extends through the boss portion '21. The lowerterminal end 29 ofthe inductor coil 26 is provided with a downwardly, thence inwardly extending portion 30 which is provided with a tubular upwardly extending sleeve 3| which extends within and is brazed to the wall of the passage 28 at the lower end thereof, the laminations being cut out to receive the coil terminal portion 38 and being insulated from this portion as indicated at 32 in Figure 4.

Theupper upwardly extending terminal end of the coil 26- is provided with a hollow fitting 33 which is provided with an upwardly extending sleeve 34 surrounded by a spherical element 35 and internally threaded nut 36. The portion 21 of element I9 is provided with-a similar sleeve 31,

spherical element38 and nut 39. The laminations are provided with a recess 40 for the reception 3 and 4- having a fluid passage 5 therebetween, of the upwardly extending portion of upper ter- 3 minal end of the coil as shown in Figures 1 and 6.

The coil 26 is wound about the laminated magnetic circuit member 2| from its lower end up ward-1y and the upper end thereof is finally :bent

inwardly from the position shown in Figure 6 to overlie the end of element IS. The fitting 33 is provided wit-h arms Bl which by means of bolts 52 and nuts 43 clamp the fitting 33 to element l9 with the upwardly extending portion of the coil of the inner conductor 2 and the portion 4'! of the outer conductor 9 which houses the longitudinally extending portions of the fittings l5 and Hi, respectively, extend beyond the remainder portions of the ends of these conductors and that insulation 48 is provided to insulate fittings l5 r and 16 from conductors 2 and 1, respectively.

In order to assemble the head I! to the arbor I, it is only necessary to position the mandrel l8 within the tube 3 of the inner conductor 2 with the fitting sleeves 34 and 31 properly aligned with the passaged fittings l6 and respectively and move the head longitudinally of the arbor to enter sleeves 3 and 31 within the passages of fittings l5 and I5, after which the nuts 36 and 39 are' threaded on the fittings t5 and 15, respectively,

and tightened. Due to the ball seating of the ball-like elements and 38 on the fittings and nuts, the balls are clamped about the sleeves to provide a fluid-tight connection.

The nuts 35 and 33 which secure the head coilterminals to the conductor fittings l6 and I5, respec-tively, thus provide the sole mechanical supporting connection between the heating head I! and arbor I.

In the operation of the head and arbor, cooling fiuid circulates downwardly through passage 5 of the inner conductor 2, through fittings l5 and 21 and passage 28, thence upwardly through the hollow coil and back through fitings 33 and I6 passage ill of the outer conductor 1, thus cooling the coil and both conductors. The current for the coil flows through the inner conductor 2 and annular element [9 to the lower coil terminal, and, thence, through the coil and back through the outer conductor I, suitable insulation, as described and shown, being provided to insure against short circuiting.

The heating head and arbor described are of the type for use in inductively heating the bores of articles wherein the heating head has close coupling with the bore surface. To this end it is essential that the connections between the head he maintained within the circumferential limits of the head.

It is to be understood that various changes may be made in the detailed construction and arrangement of the parts described without departing from the spirit and substance of the invention, the scope of which is defined by the ap pended claims.

What is claimed is:

1. In an induction heating apparatus, an arbor including a pair of parallel current conductors insulated from each other, each having a terminal fitting at one end thereof, an inducing head having a coil support and an inductor coil carried by said support, terminal connector fittings for said coil, said last-mentioned fittings being rigidl carried by said coil support, and means rigidly and removably securing said last-mentioned fittings to said first-mentioned fittings and providing with said fittings attachment connections for said head from said arbor, said fittings being in spaced relationship to form an airspace insulation between the arbor and head whereby electrical creepage current losses at said connections are substantially reduced.

2. In an induction heating apparatus, an arbor including a pair of parallel current conductors insulated from each other, each having a terminal fitting at one end thereof, an inducing head having a coil support and an inductor coil carried by said support, terminal connector fittings for said coil, said last-mentioned fittings being rigidly carried by said coil support, and means rigidly and removably securing said last-mentioned fittings to said first-mentioned fittings and providing with said fittings attachment connections for said head from said arbor, one of said conductors having a longitudinal bore and said coil support having a longitudinal mandrel projecting therefrom and closely fitting with said 1ongitudinal bore in slidable relationship thereto.

3. In an induction heating apparatus, an arbor including a pair of parallel current conductors insulated from each other, each conductor having a longitudinally extending connector fitting extending from one end thereof, an inducing head including a coil support having longitudinally ex tending connector fittings rigidly carried thereby for alignment with said first-mentioned fittings, an inductor coil carried by said support and having its ends electrically connected with said second-mentioned fittings, and nut means removably connecting said first and second mentioned fittings and constituting with said fittings an attachment connection between said head and arbor, said fittings bein in spaced relationship to form an air-space insulation between the arbor and head whereby electrical creepage current losses at said connections are substantially re duced.

4. In an induction heating apparatus, an arbor including concentric current conductors insulated from each other, an induction heating head including a support and an inductor coil carried thereby, said support and the innermost of said conductors having interfitting longitudinal portions holding said arbor and conductor against relative transverse movement only, a pair of rigid current connectors at one end of said support electrically connected with said coil, a pair of rigid current connectors at the adjacent end of said arbor electrically connected with said current conductors, and means rigidly and removably securing the first-mentioned connectors to the second-mentioned connectors, said means constituting a supporting connection between said head and arbor.

5. In an induction heating apparatus, an arbor including concentric current conductors in sulated from each other, an induction heatin head including a support and an inductor coil carried thereby, said support and the innermost of said conductors having interfitting longitudinal portions holding said arbor and conductor against relative transverse movement only, a pair of rigid current connectors at one end of said support electrically connected with said coil, a pair of rigid current connectors at the adjacent end of said arbor electrically connected with said current conductors, and means rigidly and removably securing the first-mentioned connectors to the second-mentioned connectors, said means constituting a supporting connection between said head and arbor, the connected connectors of said pairs being substantially diametrically opposite the connected connectors of the others of said pairs and being arranged with the circumferential limits of said head.

6. An induction heating head comprising a. support constituting an electrical conductor, an inductor coil surrounding said support and having one end electrically connected to one end of said support and its other end extending longitudinally beyond the other end of said support, a rigid electrical connector rigidly secured to said projecting coil end extending radially inwardly of said other end of said support, electrical in- REFERENCES CITED The following references file of this patent:

UNITED STATES PATENTS are of record in the Number Name Date 2,242,838 Somes May 20, 1941 2,288,041 Somes June 30, 1942 2,358,834 Somes Sept. 26, 1944 2,359,272 Somes Sept. 26, 1944 2,371,185 Purat Mar. 13, 1945 

